Theory of chaos transmission in dispersion optical fiber and physical mechanism of chaotic signal action on dispersion optical fiber are studied. A physical model of evolution of chaotic signal propagation in dispersion optical fiber is presented by coupling chaotic laser system with dispersion optical fiber channel. A frequency chipping of nonlinear evolution on chaotic signal in dispersion optical fiber and its expression are presented. An action of dispersion optical fiber is analyzed on chaotic signal propagation and evolution in detail.The dispersion can change the phase of frequency spectrum component of the chaotic signal,however,it cannot affect the spectrum shape of the chaotic signal. The dispersion can change the slow varying component of the chaotic signal,however,it does not change the time varying character and the distributions of power and intensity of the chaotic signal. The dispersion can change the global rotation angle of the chaotic attractor in phase space and let the rotation angle vary with optical fiber length,however,it cannot affect the internal configuration of the chaotic attractor. At last,evolutions of the phase,the slow varying component and the attractor of the chaotic signal transmission in optical fiber are numerically simulated,respectively.